Bersa Thunder Won't Slide Lock

[ChickenHawk]

Well, not reliably anyway.

Some background: Bersa Thunder .380 with 3 factory Bersa 7-round magazines; I've had the gun for about 1 1/2 months and have shot about 1000 rounds through it. I clean it after every trip to the range.

Lately, I've been shooting mostly Armscor Precision 95 grain FMJ for practice ammo. I also shoot some Cor-Bons and Speer Gold Dot, but I can't recall if this has ever happened with the better (defensive) ammo.

I love this gun.

For the past 2-300 rounds I've noticed that it doesn't reliably slide-lock when the magazine is empty. I shot 100 rounds at the range today (all Armscor) and it happened one time today. Naturally, since I am not always counting shots, I find out this happens when I pull the trigger and it goes "click!".

Any suggestions how I might resolve this? Have I lubed something I shouldn't maybe?

Thanks for any help,
ChickenHawk

 

[cslinger]

Well if it does this will all magazines the cheapest and easiest way to test/fix is the slide lock spring. You can usually order a replacement directly from the factory or from Wolff Springs. Wolff makes very good stuff but I am not sure if they make Bersa springs. They do have a web site.

I have found many manufacturers to be packing their firearms with springs that could be better as of late. CZ seems to be notorious for this lately. Then again it is not inconceivable that you simply got a bad spring out of the batch......#$% happens. Either way I don't think you will have a problem fixing this.

Cost should be very very low and it is most likely the problem. If that doesn't work I would call the factory tech support/gunsmith folks and ask.

My two cents. Good luck.

Chris

 

[horge]

I dunno, Chris. The slide catch spring is there to PREVENT slide lock until the magazine's feed platform defeats it.

I've run into the same problem, Chicken. The usual causes for failure to lock (IME) seem to have been

1. a weakened magazine spring, which doesn't get the feeder platform
up top fast enough to activate the lock before the slide comes home.

2. a dirty magazine tube, which retards the timely ascent of the
feeder platform, once again unable to push the lock up before the
slide comes home

Mags are often tested for reliable feeding of cartridges ONLY. Few give sufficient thought to the last .4 inch the spring has to push up after the last casing is ejected. The feeder platform can only haul butt that last .4 AFTER the last casing is spat out, and the boltface is out of the way

3. a weak cartridge load, which pushes the slide back far enough
to allow chambering of an 'imaginary next cartridge', but not far enough
back to give the mag's feeder platform enough time to get up (that's
about an extra 1/8" of slide travel needed). Actually, this is again
as much the fault of the mag spring or dirt in the mag.

A worn-out slide catch nub, or a worn-out catch notch in the slide is extremely unlikely, no? Both portions are hardened steel.

FWIW, the springs for the 9 and 7 round magazines are identical, and the problem, at least IME, is more prevalent with 9-round mags. Not enough oomph in the mag spring for the greater length of the niner. Do you clean your mags, Chicken?

Maybe a dry lube treatment on the inside of the magazine body/tube might help (a wet lube will potentially harm cartridges, but not retard magazine performance). You can just buy a new mag spring and compare the strength of brand-new versus your used originals. I'd sure like to know how fast these springs start to tire out.


hth


horge

PS: I didn't understand the triggerpull="click" part. Are you slapping the mag in to jiggle-release a presumed slidelock, then proceeding to pull the trigger on what you think is loaded chamber?

 

[ChickenHawk]

Great post horge, thanks for that. I appreciate your insight too Chris, but horge's right about how the spring works. That would have been way too easy!

I do not typically clean my mags. I do that on rare occassion when I'm really bored out of my brains, and that hasn't happened since I got the Bersa.

I'll try cleaning them as you suggest and will keep an eye on it. I had the same thought about it maybe being a weak cartridge charge, which is why I mentioned the ammo in my original post.

The slide catch nub and notch are both perfect looking. I'd be awfully disappointed if they were wearing down so quickly, eh!

I kinda feel the same way about the mag springs, though. If they can really lose their strength after so short a time then that would be disappointing! I may try it just for grins since the mag spring can't cost very much.

Cheers,
ChickenHawk

 

[horge]

Chicken,
I sure wish we had a 'Tuner' or 'Fuff' for Bersa 380's...
The 1911 aficionados on THR have it so good.


I think you only need to clean the top-half-or-so of the mag body/tube, so no need to always disassemble the mag (frequent disassembly wears out the spring faster, theoretically --since you're allowing FULL cycling of the spring when its out and expanded fully). Disassembly once in awhile ...like you said, maybe when one is bored, hehe..

I just push the platform down with a stick, then lock it down with a small screwdriver through the cartridge-counter holes. Cotton buds and solvent, with the mag upside down so the crap can fall out rather than in.

I find all kinds of fine grit and powder after two sessions or so. The higher up the body/tube, the filthier, not surprisingly. Then again, that depends on how dirty the ammo is to begin with

 

[ChickenHawk]

Sounds like a great way to do the job. I'll give it a try.

Do you have a favorite lube for this kind of thing? As you say, stuff like CLP (my regular) probably isn't good for the cartridges.

As a side-note, I use Slide-Glide on the rails of all my semi-autos. I suppose some may be getting on the slide catch notch and causing it to slip off the catch. It didn't look too dirty before I cleaned it (just now) though.

Thanks!

Regards,
ChickenHawk

 

[horge]

Originally posted by Chickenhawk, Musher of chickens
Do you have a favorite lube for this kind of thing? As you say, stuff like CLP (my regular) probably isn't good for the cartridges.

No, I don't -- I just clean.
If I could find a 'dry' lube (and the money for it), I might try it.
Wanna send me some, Chicken? For ehrmmm...
testing and evaluation purposes. Send me a few cases of your ammo too.

Originally posted by Chickenhawk, Musher of chickens
As a side-note, I use Slide-Glide on the rails of all my semi-autos. I suppose some may be getting on the slide catch notch and causing it to slip off the catch. It didn't look too dirty before I cleaned it (just now) though.

I can't see how 'Slide-Glide' could contribute to a failure to slidelock (FTSL? )
Never used that goopy stuff, but the notch in the slide is sharply cut enough, and I presume the lube, while admittedly dense, will deform/displace fast enough to allow the catch-nub to lock on.
I certainly run into the same failure without using goop, but who knows?
If the goop is sticky enough to really fight the slide's rearward motion... then yeah, I think/guess that might cause a problem (just like with a weak cartridge).

 

[ChickenHawk]

Originally posted by Chickenhawk, Musher of chickens

LOL!!

That little guy has always been my favorite cartoon character!

Anyway, thanks again for the help.

Cheers,
Chickenhawk

 

[71Commander]

http://www.bersa-llama.com/380liteSpts.html

Click on the blue parts list link for an exploded view.

On another note, I have 3 mag, but only 2 are loaded at any one time. I wonded how often I should rotate the empty one to keep the constant pressure off of the spring

 

[horge]

Hi Tenn T

Mechanically speaking, keeping a spring compressed shouldn't wear it out, at least it virtually won't.
It is the cycling (compression-decompression) of a spring that does.
Thus, theoretically, rotating your mags can wear them out even faster

..'course, if the springwire is substandard/soft (untreated), then prolonged compression will kill it over time.